Propanoic acid, 2-hydroxy-, ammonium salt (1:1), (2S)-

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

ca. 26.34 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: total NH3-N

Basis for effect:

mortality

Remarks on result:

other: 95 % CI = 24.19-28.85

Duration:

48 h

Dose descriptor:

LC0

Effect conc.:

ca. 10.4 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: total NH3-N

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

LC100

Effect conc.:

ca. 3.34 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: unionised NH3-N

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

ca. 2.94 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: unionised NH3-N

Basis for effect:

mortality

Remarks on result:

other: 95 % CI = 2.70-3.22

Duration:

48 h

Dose descriptor:

LC0

Effect conc.:

ca. 1.16 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: unionised NH3-N

Basis for effect:

mortality

Details on results:

In the original publication, effect levels are reported as unionised ammonia only, although the analytical measurements (ammonia-selective electrode) were based on total ammonia. Calculations were done based on the temperature- and pH-dependent dissociation percentages (percent unionised ammonia) reported by Thurston et al. (1979). The target parameters in the context of this dossier are effect values based on total ammonia. For back-calculating the reported LC50 of 2.94 mg/L (unionised NH3), the percentage of unionised NH3 at 20 °C and pH 8.5 was used, which is representative for the actual test conditions.
At 20 °C and pH 8.5, 11.16 % of the ammonia is available in unionised form. Accordingly, the LC50 based on total ammonia is calculated to be 26.34 mg/L (total NH3-N).

Validity criteria fulfilled:

yes

Remarks:

Conducted according to ASTM guideline, but OECD 202 validity criteria are fulfilled.

Conclusions:

The 48 h LC50 of ammonia in Daphnia magna was determined to be 2.94 mg unionised NH3-N/L, corresponding to 26.34 mg total NH3-N/L.

Executive summary:

The 48-h acute toxicity of ammonium chloride to Daphnia magna was studied under static conditions. Daphnids were exposed to the control and the test chemical for 48 hours at measured concentrations not reported in detail. Mortality was observed daily. The 48-hour LC₅₀ in terms of total ammonia was 26.34 mg/L.

This study is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.

Results synopsis

Test organism age: Neonates (< 24 h)

Test type: Static

LC₅₀: 26.34 mg /L; 95 % CI = 24.19–28.85 mg/L (total NH3-N)

NOEL: 10.40 mg (total NH3-N)

Endpoint(s) effected: Mortality

This information is used in a read-across approach in the assessment of the target substance. For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

For details and justification of read-across please refer to the attached report in section 13 of IUCLID.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

130 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

250 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Details on results:

Test solutions were not neutralised. Effects on the mobility of the daphnids are hence likely to be caused by the low pH value. At the highest test concentration a pH of 3.6 (t = 0 h) was measured.

The apparent toxicity of lactic acid to Daphnia can be explained by the low pH values of the test substance solutions. At the highest test concentration a pH of 3.6 (t = 0 h) was measured.

Validity criteria fulfilled:

yes

Conclusions:

The 48 h EC50 (immobilisation) of lactic acid to Daphnia magna is 130 mg/L, which can be attributed to a pH effect.

Executive summary:

The acute toxicity of the test material, a solution of about 80 % L-(+)-lactic acid, to the fresh-water crustacean Daphnia magna was determined as described in the OECD guideline no. 202 and according to the OECD principles of Good Laboratory Practice.

The test was carried out with 4 × 5 daphnias (quadruplicate test solutions) at each concentration, and the test solutions were not replaced. The exposure duration was 48 hours. The nominal concentrations tested were 32, 56, 100, 180, 320 and 560 mg/L.

At the start of the test the test substance appeared to be completely dissolved at all concentrations tested (visually assessed).

The actual concentrations of L-(+)-lactic acid were determined enzymatically with a Boehringer test kit. They were between 42 and 76 % of nominal just after dosing (average 59 %). To test the stability, the concentrations of L-(+)-lactic acid were also analysed at the end of the test and were between 58 and 78 % of nominal (average 71 %).

The results of the test were (as nominal concentrations):

24 h EC50 (mobility): 240 mg/L

48h EC50 (mobility): 240 mg/L

48h EC100 (mobility) 320 mg/L

The 48-h EC50 based on measured concentrations was 130 mg/L.

The apparent toxicity of lactic acid to Daphnia can be explained by the low pH values of the test substance solutions. At the highest test concentration a pH of 3.6 (t = 0 h) was measured.

This information is used in a read-across approach in the assessment of the target substance. For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

ca. 61.3 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

dissolved

Remarks:

total ammonia

Basis for effect:

mobility

Remarks on result:

other: 19.7 °C, pH 8.58-8.11

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

ca. 4.07 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

dissolved

Remarks:

un-ionized ammonia (NH3)

Basis for effect:

mobility

Remarks on result:

other: 19.7 °C, pH 8.58-8.11

Reported statistics and error estimates:

Median lethal concentration (LC50) values in the acute toxicity tests were determined using the trimmed Spearman-Karber method (Hamilton et al. 1977). When it was necessary to adjust for mortality in the control, Abbott's formula was used (American Public Health Association et al. 1976).

Validity criteria fulfilled:

not applicable

Remarks:

non-guideline study, but scientifically solid result published in peer-reviewed article

Conclusions:

Effects of ammonia on Daphnia magna were studied. The LC50 (48 h) was determined to be 4.07 mg/L for unioniSed ammonia (NH3) and 61.3 mg/L for total ammonia.

Executive summary:

The 48-h acute toxicity of ammonium chloride to Daphnia magna was studied under flow-through conditions. Daphnids were exposed to the control and the test chemical for 48 hours at measured concentrations not reported in detail. Mortality was observed daily. The 48-hour LC₅₀ in terms of total ammonia was 61.3 mg/L.

This study is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.

Results synopsis

Test organism age: Neonates (< 24 h)

Test type: Flow-through

LC₅₀: 61.3 mg /L (total NH3-N)

Endpoint(s) effected: Mobility

This information is used in a read-across approach in the assessment of the target substance. For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Description of key information

Different ECx values were experimentally determined for Daphnia magna according to different standardised methods (OECD 202, ASTM, EPA OTS 797.1300).

Three studies and one review article are available for aquatic invertebrates which can be used for read-across to ammonium-S-lactate: Gersich (1986) and Reinbold (1982) describe the toxicity of ammonium, while Hooftmann (1992) and Bowmer (1998) report the toxicity of L(+)-lactic acid. Therefore, the toxicity of the target substance (ammonium-S-lactate) is described by read-across to the ionic species of which it is composed.

LC₅₀ (48 h): 26.34 mg/L (total NH₃-N; Gersich, 1986). Stoichiometrically, the fraction of ammonium-N in ammonium-(S)-lactate is 12.96 %. The EC₅₀ for ammonium-(S)-lactate is thus calculated at 203.3 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

ca. 203.3 mg/L

Additional information

LC₅₀ (48 h): 61.3 mg/L (total NH₃-N; Reinbold 1982)

EC₅₀ (48 h): 240 mg/L (lactic acid; Bowmer, 1998)

EC₅₀ (48 h): 130 mg/L (lactic acid; Hooftman, 1992).

The apparent toxicity of lactic acid to Daphnia magna can be explained by the low pH values of the test substance solutions. At the highest test concentration a pH of 3.6 (t = 0 h) was measured.

Accordingly, the toxicity of ammonium-(S)-lactate is largely determined by the ammonium ion.